Huntington's disease (HD) is a progressive, inherited, degenerative brain disorder that produces physical, mental and emotional changes. Named for George Huntington, the physician who first described the illness in 1872, Huntington's Disease used to be known as Huntington's chorea, from the Greek for choreography, or dance. The name refers to the involuntary, jerky movements that can develop in later stages of the illness.
Although it is less common than some conditions characterized by similar symptoms, such as Parkinson's or Alzheimer's disease, approximately one person in 30,000 in the United States has Huntington's Disease. Huntington's Disease affects someone's ability to think, talk and move by destroying cells in the basal ganglia, the part of the brain that controls these capacities. Caused by a gene mutation that leads to a toxic accumulation of protein in the brain, Huntington's is inherited from either one or both parents.
Every child of a parent who carries the HD gene has a 50% chance of inheriting the abnormal gene. Pre-symptomatic testing (see below) can determine whether someone is likely to develop the disease. A child who inherits the Huntington's gene will eventually develop the illness, although onset typically does not occur until ages 35-50 or later. The good news: if a child does not inherit the Huntington's gene, there is no risk of developing Huntington's Disease or of passing it on, since Huntington's does not "skip" generations.
Signs and symptoms of Huntington's Disease
Because Huntington's Disease affects the mind, body, and emotions, symptoms often mimic other conditions. The general symptoms in early stages can include poor memory; difficulty making decisions; mood changes such as increased depression, anger or irritability; a growing lack of coordination, twitching or other uncontrolled movements; difficulty walking, speaking, and/or swallowing. The order in which symptoms develop will vary from person to person.
Below is a summary of symptoms by type: physical, mental, and emotional.
- Development of tics (involuntary movement) in the fingers, feet, face, or trunk
- Increased clumsiness
- Loss of coordination and balance
- Slurred speech
- Jaw clenching or teeth grinding
- Difficulty swallowing or eating
- Continual muscular contractions
- Stumbling or falling
- Decreased concentration
- Forgetfulness and memory decline
- Poor judgment
- Difficulty making decisions or answering questions
- Difficulty driving
Over time, these symptoms may progress to a stage where the person loses the ability to recognize familiar objects, people and places.
Initial emotional symptoms are usually subtle, and thus easy to misinterpret. Many conditions and life circumstances can trigger mood changes, so it is especially important to know what psychiatric signs may indicate Huntington's. Depression, the most common psychiatric symptom of Huntington's Disease, will generally manifest as:
- Lack of energy
- Ongoing disinterest in life (lack of pleasure or joy)
- Bipolar disorder (manic-depression) in some Huntington's patients.
A person with Huntington's Disease may eventually begin to exhibit psychotic behavior, such as:
- Inappropriate behavior (e.g., unprovoked aggression)
Diagnosing Huntington's Disease
Genetic testing can diagnose Huntington's at every stage of the life cycle.
There are three categories for testing:
- Prenatal testing, either amniocentesis (a sample of fluid from around the fetus), or chorionic villus sampling (CVS—a sample of fetal cells from the placenta), will indicate whether the baby has inherited the gene for Huntington's.
- Pre-symptomatic testing is available to people who are at risk of inheriting Huntington’s Disease from a parent, but don’t have symptoms and don’t know whether or not they carry the gene.
- Confirmatory testing determines whether a person showing what appear to be the symptoms of HD, actually has the disease. Neurological and psychological tests are also conducted to arrive at a conclusive diagnosis of Huntington's Disease.
Pre-symptomatic testing is usually requested or recommended when a parent is known to have, or is suspected of having, Huntington's Disease, or an at-risk parent is still living, but doesn't know whether they carry the Huntington's gene.
Testing a child under 18
If someone's grandparent has Huntington's Disease but the parent doesn't know their carrier status, the grandchild has a one in four chance of developing the disease. This can be an emotionally charged issue, because revealing the tested individual's HD status also reveals whether or not their parent carries the gene. It is therefore crucial to discuss the testing option with family members who will be affected by the outcome.
Testing asymptomatic children under age 18 presents a similarly controversial issue. It is generally recommended that pre-symptomatic children not be tested until they can manage this decision for themselves. Parental consent must be given if an under-age child is tested. Usually a neurological examination is carried out before pre-symptomatic testing to confirm that an individual has not already developed the disease. And, pre-symptomatic testing cannot predict at what age symptoms will begin to occur.
Treatment for Huntington's Disease
The emphasis today is on living positively with Huntington's Disease. An integrated, multi-disciplinary approach focuses on the triad of:
- diet and supplements
- spiritual and psychosocial support
This well-rounded program enhances quality of life for people living with Huntington's Disease, as well as for those at risk of developing HD, and may very likely delay the onset of symptoms. Foods known to nourish the brain, support memory and build overall immunity are especially recommended.
See Improving Your Memory: Tips and Techniques for exercises and dietary suggestions that boost brain function.
Once Huntington's Disease is confirmed, patients are encouraged to continue this healthy lifestyle approach, adding other health support therapies as they become necessary, including physical, occupational, and/or speech therapy. Medications are available to treat the symptoms of Huntington's Disease, and your physician can help determine whether these might be appropriate for you.
Prognosis and research being done toward a cure
Although there is not yet a cure for Huntington's Disease, the research being done is encouraging in terms of slowing the progression of the disease. Since Congress established the Commission for the Control of Huntington's Disease and Its Consequences in 1977, it has provided consistent support for federal research. The efforts to understand and reverse Huntington’s Disease include the following:
|Current Research Efforts for Huntington’s Disease|
Investigators in the field of neurobiology—which encompasses the anatomy, physiology, and biochemistry of the nervous system—continue to study the Huntington's gene with an eye toward understanding how it causes disease in the human body.
Neurologists, psychologists, psychiatrists, and other investigators are researching potential treatments that will then undergo clinical trials in humans.
Leading-edge technologies are enabling scientists to understand how the defective gene affects brain tissue, body chemistry and metabolism.
Research is being done with mice to mimic the human disease and test potential treatment modalities.
|Current Research Efforts for Huntington’s Disease|
Basic neurobiology - Investigators in the field of neurobiology—which encompasses the anatomy, physiology, and biochemistry of the nervous system—continue to study the Huntington's gene with an eye toward understanding how it causes disease in the human body.
Clinical research - Neurologists, psychologists, psychiatrists, and other investigators are researching potential treatments that will then undergo clinical trials in humans.
Imaging - Leading-edge technologies are enabling scientists to understand how the defective gene affects brain tissue, body chemistry and metabolism.
Animal models - Research is being done with mice to mimic the human disease and test potential treatment modalities.
Resources & References
Huntington's Disease: Hope Through Research – Background on the origins, causes, treatment and research into Huntington's Disease. (NINDS)
Huntington's Disease – Comprehensive article includes signs, symptoms, risk factors, when to seek medical advice, complications, self-care and treatment for Huntington's Disease. (Mayo Clinic)
Caring for People with Huntington's Disease – Resource site for caregivers, focusing on topics from feeding to behavioral issues to home safety. Many links for delving deeper, including links to International Organizations and Support Groups, a study group in the UK, and an on-line discussion group. (University of Kansas Medical Center)
HD Getting Started – A Huntington's Disease information clearinghouse, providing the latest research updates and protocols on the treatment horizon. Focuses on the triad of exercise, diet and spirituality as offering hope for slowing down or preventing HD. (HD Lighthouse.org)